Handheld two-way radio users are familiar and accustomed to rotary controls. Such controls on a radio can include for example volume control, channel selection, and squelch control among others. A rotary control for a two-way radio must have sufficient turning torque to prevent inadvertent actuation of the control. In certain environments, such as public safety environments, users for example firefighters and rescue personnel are often wearing gloves. Handheld radios developed for use in these conditions often provide a wider diameter rotary control—considered to be a more “glovable” control. However, inadvertent or unintentional actuation can become problematic with larger diameter, glovable controls.
To minimize inadvertent actuation of a rotary control, the torque may increased by adding friction, for example via an o-ring. Unfortunately, approaches which increase friction can often “mute” the tactile feedback to the user. The tactile feedback of a rotary control may take the form of a clicking feel for the multiple positions of the rotary control. Muting the clicks of the rotary control makes it more difficult for the user to manage the control.
The torque of a rotary control can also be increased by using a significantly larger switch with larger torque. Since products are generally decreasing in size, traditional rotary controls tend to be mounted in close proximity to other controls on a given product. As such, larger switches are not feasible when dealing with small, volume constrained portable devices, such as handheld two-way radios. The grip area accessible by users for these rotary controls traditionally extends to the control surface of a product.
Accordingly, there is a need for increasing the switching torque of a small sized rotary control, without muting tactile feedback particularly in the form of clicks.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.